JP2010149109A - Catalyst for producing high calorie gas, production method therefor, and method for producing high calorie gas using catalyst for producing high calorie gas - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a catalyst for producing a novel ruthenium-based high calorie gas, which can generate at a relatively low temperature a saturated hydrocarbon gas component other than methane at a high concentration in a high calorie gas and to provide a technique for highly efficiently producing a high calorie gas using such catalyst for producing a high calorie gas while achieving energy saving. <P>SOLUTION: The catalyst comprises a metal oxide carrier supporting an iron group element and ruthenium supported by a wet reduction method thereon. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technique for producing a gas having a higher calorie than a methane gas generally used as a city gas from a mixed gas containing hydrogen and carbon monoxide, and more specifically, by using a ruthenium-based catalyst, carbon other than methane. The present invention relates to a technique for supplying a fuel gas containing a saturated hydrocarbon gas of several to four as one of the main components (in the present invention, this is referred to as a high calorie gas).

The fuel gas currently supplied as city gas is a high-calorie gas in which liquefied petroleum gas such as butane is mixed so that the calorific value is 45 MJ / Nm ³ with methane gas as the main component. The main source of city gas is liquefied natural gas (LNG), but in recent years, alternative natural gas obtained by steam reforming and methanation such as naphtha to cope with the increasing demand and depletion of petroleum and LNG. SNG) is being researched and developed.

General SNG is synthesized by a nickel-based catalyst using, as a raw material, a mixed gas containing hydrogen and carbon monoxide obtained by gasifying naphtha, coal, oil sand and the like. This reaction proceeds by the reactions (1) and (2) shown in Chemical Formula 1. However, SNG synthesized in this way is mainly composed of methane (n = 1) and carbon dioxide, and as it is, calories are low (39.8 MJ / Nm ³ even if converted to pure 100% methane). Therefore, there is a situation that liquefied petroleum gas such as butane must be mixed, calorie adjusted, and used as fuel gas. In addition, SNG has a disadvantage that it cannot be supplied as fuel gas unless a purification process such as removal of inert gas is performed, and the manufacturing process is complicated due to the need for subsequent processes such as a purification process and a calorie adjustment process. It has become a problem of conversion.

[Chemical formula 1]
nCO + (2n + 1) H ₂ → C _n H _{2n + 2} + nH ₂ O (1)

CO + H ₂ O → CO ₂ + H ₂ (2)

  Therefore, various methods (mainly catalyst improvements) have been researched and developed as a technique for producing a high calorie gas containing a saturated hydrocarbon gas component other than methane.

  For example, Patent Document 1 discloses an iron / graphite-based intercalation compound that uses a mixed gas containing hydrogen and carbon monoxide and can convert a carbon monoxide gas to almost 100% to obtain a product gas containing ethane. A catalyst having a main component is described. However, this catalyst has a relatively high reaction temperature of 400 ° C., and the generated gas cannot be said to have a sufficiently high calorie, and is improved from the standpoint of the production process such as energy saving of reaction energy and adjustment of calorie. There was room for.

  In contrast, molybdenum carrying a fourth-period transition element such as manganese, cobalt, nickel, etc., capable of producing a saturated hydrocarbon gas component other than methane at a high concentration from a mixed gas containing hydrogen and carbon monoxide. An oxide catalyst is described in US Pat. This catalyst can improve the selectivity to ethane, propane, and butane in the product gas by supporting the fourth period transition element between the molybdenum oxide layers. However, according to this catalyst, the reaction temperature is still high, and there remains room for improvement in terms of energy saving. Further, the conversion rate of carbon monoxide gas is low, and there is room for improvement in terms of the manufacturing process.

  Further, Patent Document 3 also describes a ruthenium-based catalyst that can generate a saturated hydrocarbon gas component other than methane at a high concentration from a mixed gas containing hydrogen and carbon monoxide. This catalyst is obtained by adding alkali metal, sulfur and ruthenium to manganese oxide. However, even such a catalyst has a high reaction temperature and a low carbon monoxide gas conversion rate, and there is room for improvement in terms of both energy saving and manufacturing process.

  Therefore, Patent Document 4 discloses that a saturated hydrocarbon gas component other than methane is produced at a high concentration from a mixed gas containing hydrogen and carbon monoxide at a relatively low reaction temperature with a high carbon monoxide gas conversion rate. A ruthenium-based catalyst is disclosed. In this catalyst, three components of iron, cobalt, manganese, and ruthenium are supported on an alumina carrier by a firing method on a carrier such as alumina and titania, and further mixed with a zeolite catalyst. However, the ruthenium-based catalyst described in Patent Document 4 must be synthesized from a large number of components and, when used, requires a reduction treatment with hydrogen gas. It is difficult to do this, and there is room for improvement because the process for producing high-calorie gas and the process for producing the catalyst itself are complicated. Further, this catalyst is not sufficiently durable against water vapor, and it is desired to improve the stability over time.

JP-A-53-075042 JP 59-166242 A JP 61-091139 A JP-A 63-241099 (Synthesis Example 3, Example 5)

  In view of the above circumstances, the present invention provides a novel ruthenium-based high calorie gas production catalyst capable of producing a high concentration of saturated hydrocarbon gas components other than methane in a high calorie gas at a relatively low temperature. Therefore, an object of the present invention is to provide a technique for producing a high calorie gas with energy saving and high efficiency by using such a catalyst for producing a high calorie gas.

  As a result of diligent research, the present inventors have examined the performance of the catalyst obtained under various conditions in the catalyst on which ruthenium used as a catalyst for producing high calorie gas is supported. When the degree is 20% or more, it has been found that the catalyst can produce a high calorie gas at a relatively low temperature and at a high carbon monoxide conversion rate by the cooperative action of ruthenium and an iron group element. . Further, it has been found that ruthenium is supported on a carrier by a wet reduction method so that the ruthenium dispersity is supported at a high dispersity of 20% or more.

〔Constitution〕
The present invention has been made based on the above new findings,
The characteristic configuration of the catalyst for producing a high calorie gas of the present invention for solving the above technical problem is as follows.
Ruthenium and iron group elements are supported on a metal oxide carrier, and the degree of ruthenium dispersion is 20% or more.
Here, the ruthenium dispersity represents the ratio of the number of ruthenium atoms capable of chemisorbing carbon monoxide out of the total number of atoms of the supported ruthenium, as shown in the following formula. That is, the ratio of ruthenium atoms that can be exposed to the surface and function as a catalyst among all the supported ruthenium atoms is shown. The amount of carbon monoxide adsorbed on ruthenium can be determined by “a metal surface area measurement method by the CO pulse method” standardized by the Catalysis Society of Japan (Reference Catalyst Committee, Catalysts, 31, 317 (1989)).

[Dispersity of ruthenium (%)] = [Carbon monoxide adsorption amount (mol) of ruthenium] / [Amount of supported ruthenium (mol)] × 100

In this case, it is preferable that ruthenium is supported on the metal oxide support by a wet reduction method.
Further, it is preferable that ruthenium is further supported by a wet reduction method on a metal oxide support on which an iron group element is supported.
Further, an iron group element may be further supported by a wet reduction method on a metal oxide support in which ruthenium is supported on the metal oxide support by a wet reduction method.

[Function and effect]
The catalyst for producing a high calorie gas of the present invention is based on the above new knowledge, because ruthenium is supported on the metal oxide support with a high dispersity of 20% or more, adsorbs a lot of carbon monoxide, Due to the cooperative action of ruthenium and iron group elements, high calorie gas can be produced at a relatively low temperature of about 300 ° C. to 350 ° C. and at a high carbon monoxide conversion rate without using other components such as a promoter. It can be manufactured.

The higher the ruthenium dispersibility, the smaller the average particle size of the supported ruthenium, and there are many highly active portions of the catalytic reaction. The average particle diameter of the supported ruthenium can be specified by X-ray diffraction analysis or electron microscope observation. In the X-ray diffraction analysis, the average particle size of the supported metal or compound can be obtained from the following Scherrer equation.
D = Kλ / (βcosθ)
Here, D (nm) represents the size of the crystallite and corresponds to the average particle diameter of the supported metal or compound. λ (nm) is the X-ray wavelength, θ (°) is the diffraction angle, β (rad) is the half-value width of the diffraction line peak, K (−) is a constant derived from the particle shape, Assuming K = 0.9. When X-ray diffraction analysis was performed on a catalyst having a ruthenium dispersity of less than 20%, diffraction line peaks appeared at positions of 2θ = 28.02 ° and 35.07 °, which are diffraction angles corresponding to ruthenium oxide. The target of the X-ray source at this time is copper, and the wavelength λ of the X-ray is 0.1541 nm (characteristic X-ray Kα ₁ ). From the half width of the diffraction line peak that appeared, the average particle diameter of the supported ruthenium was 12 to 27 nm. On the other hand, when X-ray diffraction analysis was performed on a catalyst having a ruthenium dispersity of 20% or more, no diffraction line peak appeared at a diffraction angle corresponding to ruthenium oxide or a diffraction angle corresponding to metal ruthenium. This indicates that the crystallite is so small that incident X-rays cannot be diffracted, that is, the average particle size of the supported metal or compound is small. When the surface of the catalyst having a ruthenium dispersity of 20% or more was observed with a transmission electron microscope, the supported ruthenium and iron were both observed in an aggregated state with a particle diameter of 10 nm or less. From this, in order to obtain a highly active high calorie gas production catalyst, the average particle size of the supported ruthenium (including ruthenium oxide) needs to be 10 nm or less, and the average particle size is Since it is 10 nm or less, it is considered that the ruthenium dispersity is 20% or more.

As a method for producing a catalyst for producing such a high calorie gas, typically, a metal oxide carrier is first supported with an iron group element, and then ruthenium is supported by a wet reduction method. It has been experimentally found that ruthenium is supported on the surface of the object carrier with a high degree of dispersion of 20% or more on the surface layer side of the layer on which the iron group element is supported.
Also, ruthenium and iron group element are supported on the metal oxide support by wet reduction method simultaneously, or after ruthenium is supported on the metal oxide support by wet reduction method, iron group element is supported by wet reduction method. It was experimentally found that ruthenium was supported with a high degree of dispersion of 20% or more.

  In these cases, a part of the supported ruthenium is covered with the iron group element, but the ruthenium exposed on the surface is maintained in a highly dispersed state, and the ruthenium dispersity becomes 20% or more. Therefore, many highly active portions in which ruthenium comes into contact with the mixed gas containing hydrogen and carbon monoxide are produced, and it is considered that a highly active catalyst for producing a high calorie gas can be obtained.

From these results, when ruthenium is supported on the support by the wet reduction method, the resulting ruthenium becomes fine particles, and thus is dispersed on the support with a high degree of dispersion, which is useful as a catalyst for producing high calorie gas. I found out that

  Further, when ruthenium is supported while the iron group element is supported on the carrier, the ruthenium is supported on the surface of the carrier and also on the surface of the iron group element. For this reason, the supported rutheniums are bonded to the iron group element, so that a phenomenon such as agglomeration and a decrease in the degree of dispersion is unlikely to occur. It is considered that the aggregation is hindered and the degree of dispersion is hardly lowered.

  Therefore, as a catalyst for producing a high calorie gas in which the degree of dispersion of ruthenium is increased to 20% or more, ruthenium is supported by a wet reduction method, or after an iron group element is supported on a metal oxide support. If it is obtained by loading ruthenium by a wet reduction method, a desired catalyst for producing a high calorie gas can be provided. Particularly preferably, the metal oxide support obtained by supporting the iron group element by the wet reduction method and then supporting the ruthenium by the wet reduction method, particularly the iron group as well as the dispersibility of ruthenium. Since the degree of dispersion of the elements is high, it is considered that the activity as a catalyst for producing a high calorie gas is high and the performance is stable.

〔Constitution〕
The iron group element is preferably iron, and the metal oxide support is preferably composed mainly of titania. Further, it is preferable that 0.5% by mass to 10% by mass of iron is supported on the metal oxide support, and 1% by mass to 8% by mass of ruthenium is preferably supported on the metal oxide support. .

[Function and effect]
Here, the iron group element has an action of biasing the component ratio of the saturated hydrocarbon produced by the carbon chain bonding reaction known as the Fischer-Tropsch reaction to the high-calorie component, and usually alone as a catalyst. When used, the reaction proceeds until liquid saturated hydrocarbons are generated, but since the methanation reaction with ruthenium proceeds with high activity, the Fischer-Tropsch reaction, due to their cooperation, It can be selectively stopped with about 2 to 4 carbon atoms. That is, high calorie gas can be selectively produced.

  Here, the iron group elements include iron, cobalt, and nickel. Usually, these have similar properties, and it has been confirmed that iron and cobalt can be effectively used in the present invention. Is used, the component of the high calorie gas to be produced contains a higher concentration of saturated hydrocarbon gas having about 2 to 4 carbon atoms (the main component is not too biased to methane, It is preferable to use iron because it is difficult to produce liquid components.

  Further, as the metal oxide carrier, metal oxides such as silica, alumina, zirconia, titania, silica alumina and the like are used. Among them, titania is preferable, and by using titania, a reaction temperature for producing a high calorie gas is set. It can be kept low. As a result, it is considered that the content of saturated hydrocarbon gas having about 2 to 4 carbon atoms in the generated high calorie gas can be improved.

  In addition, it is preferable that the load of iron supported on the metal oxide support is 0.5 mass% to 10 mass%. This is because if the amount of iron supported is less than 0.5% by mass, the saturated hydrocarbon gas content of about 2 to 4 carbon atoms contained in the product gas cannot be sufficiently increased, and the amount of iron supported is This is because when the content exceeds 10% by mass, the activity of the high calorie gas production catalyst as a whole tends to decrease. In addition, it is more preferable that the amount of iron supported on the metal oxide support is 0.5% by mass to 3% by mass from the examples described later.

  Further, the amount of ruthenium supported on the metal oxide support has the following tendency. That is, when the amount of ruthenium supported is less than 1% by mass, the catalyst for producing high-calorie gas as a whole has fewer catalyst active points (lower activity) and the reaction does not proceed easily. Therefore, the reaction using the catalyst for producing the high calorie gas has to increase the temperature, the energy efficiency is lowered, and the methane gas selectivity in the generated gas is increased with the increase of the reaction temperature. End up. As a result, it becomes difficult to obtain a gas having a sufficiently high calorie. On the other hand, when the amount is more than 8% by mass, the methane generation activity of ruthenium itself is too dominant, and the selectivity of methane gas in the generated gas is increased, so that it is difficult to obtain a gas having a sufficiently high calorie. For these reasons, the supported amount of ruthenium is preferably 1% by mass to 8% by mass. Further, from the examples described later, it is more preferable that the amount of ruthenium supported on the metal oxide carrier is 2 mass% to 6 mass%.

〔Constitution〕
In addition, the characteristic configuration of the method for producing a high calorie gas production catalyst of the present invention is that ruthenium and an iron group element are dispersed and supported on a metal oxide support so that the degree of ruthenium dispersion is 20% or more. is there.
Here, it is preferable that ruthenium is supported on the metal oxide support by a wet reduction method, or after supporting an iron group element on the metal oxide support, ruthenium is preferably supported by a wet reduction method. It is preferable that ruthenium is supported on the oxide carrier by a wet reduction method and then an iron group element is supported by a wet reduction method.

  The iron group element is preferably iron, and the metal oxide support is preferably composed mainly of titania. Further, it is preferable that 0.5% by mass to 10% by mass of iron is supported on the metal oxide support, and 1% by mass to 8% by mass of ruthenium is preferably supported on the metal oxide support. .

[Function and effect]
That is, the catalyst for producing high calorie gas produced by these characteristic configurations can carry ruthenium with high dispersity as described above, and is considered suitable for producing high calorie gas. It is done.

〔Constitution〕
Furthermore, the high-calorie gas production method according to the present invention is characterized in that a mixed gas containing hydrogen and carbon monoxide is reacted in the presence of the aforementioned high-calorie gas production catalyst.

[Function and effect]
When the mixed gas containing hydrogen and carbon monoxide is reacted using the highly active high calorie gas production catalyst, the carbon monoxide gas in the mixed gas is reduced by hydrogen under the ruthenium catalyst, It is methanated and a carbon-carbon chain is formed by an iron group element. Therefore, when the mixed gas reacts, a mixture of methane and a saturated hydrocarbon having 2 to 4 carbon atoms is provided by the cooperative action of the ruthenium and the iron group element. Therefore, a high calorie gas can be produced by efficiently producing methane and a mixture of gaseous saturated hydrocarbons located between methane and liquid saturated hydrocarbons.

  The ruthenium supported on the carrier in the present invention is usually considered to be supported in a metallic state, such as when it is supported under wet reduction conditions, but within a range that does not depart from the form of functioning as a catalyst. , Oxides, and salts such as nitrates and chlorides used when impregnating and supporting may be included. In the present invention, these various forms of ruthenium are collectively referred to simply as ruthenium. The same applies to the case of an iron group element.

  Therefore, in the present invention, by providing a high calorie gas production catalyst and its production method, the high calorie gas production method of the present invention makes it possible to produce high calorie gas with energy saving and high efficiency, In response to increasing global energy demand and depletion of energy resources, we were able to provide technology to enable new forms of fuel gas supply.

Figure showing the ruthenium loading dependence of hydrocarbon selectivity of high calorie gas production catalyst The figure which shows the iron loading dependency of the hydrocarbon selectivity of the high calorie gas production catalyst

  Below, the catalyst for high calorie gas production of the present invention is explained. Preferred examples are described below, but these examples are described in order to more specifically illustrate the present invention, and various modifications can be made without departing from the spirit of the present invention. The present invention is not limited to the following description.

  In the high calorie gas production catalyst of the present invention, ruthenium is further supported on a metal oxide support on which an iron group element is supported with a degree of dispersion of 20% or more by a wet reduction method.

More specifically, for example, iron as an iron group element is supported on titania as a metal oxide carrier by a wet reduction method. Next, ruthenium is supported by a wet reduction method to obtain the high calorie gas production catalyst of the present invention.
The obtained high calorie gas production catalyst is accommodated in a reaction vessel, and a mixed gas containing hydrogen and carbon monoxide is circulated so as to come into contact with the high calorie gas production catalyst in the reaction vessel. The gas discharged from the gas is recovered to obtain the product gas as a high calorie gas.
Hereinafter, more specific examples will be described.

[Example 1]
In Example 1, the reactants (a) to (e) are used.
(A) 10 g of spherical titania having a diameter of 2 to 4 mm
(B) Aqueous solution containing 1.45 g of iron (III) nitrate nonahydrate (Fe (NO ₃ ) ₃ .9H ₂ O) (c) 0.375N aqueous sodium hydroxide solution (d) 0.3% hydrazine Aqueous solution (e) An aqueous solution containing 0.43 g of ruthenium (III) chloride (ruthenium content: 47.3 mass%)

(Iron-supporting titania)
The carrier (a) is impregnated with the entire amount of the iron nitrate aqueous solution (b) and dried (impregnation method). Furthermore, the obtained carrier was fired at 400 ° C. for 6 hours (baking method) to obtain iron-supporting titania.

(Iron-ruthenium-supported titania: catalyst A)
Next, the iron-supporting titania is impregnated with a ruthenium chloride aqueous solution (e) in half of the prescribed amount and dried. Then, the remaining half of the ruthenium chloride aqueous solution (e) is impregnated and dried. Furthermore, the obtained support | carrier was immersed in sodium hydroxide aqueous solution (c), and the ruthenium was fixed to the support | carrier. The carrier was washed with water, dried, and then reduced with 90 ml of a hydrazine aqueous solution (d) at room temperature for 1 hour (wet reduction method) to obtain iron-ruthenium-supporting titania as a catalyst for producing a high calorie gas. This high calorie gas production catalyst is referred to as Catalyst A. The supported ruthenium is deposited to a thickness of several tens to several hundreds of μm, and ruthenium compounds such as ruthenium oxides, chlorides and hydroxides are mixed with ruthenium in a metallic state near the surface layer. .
About the obtained catalyst for high-calorie gas production (Catalyst A), a reaction test 1 relating to the production of high-calorie gas was conducted.

[Reaction Test 1]
A mixed gas containing hydrogen and carbon monoxide was reacted in the presence of the catalyst A.
The iron content of the catalyst A with respect to titania is 0.2 g in terms of iron (III) nitrate nonahydrate, and the content is 2 mass% with respect to 10 g of titania. Similarly, the content of ruthenium with respect to titania is 2% by mass. Further, when the degree of dispersion of ruthenium with respect to titania was measured by the carbon monoxide adsorption method, it was found that the degree of dispersion was as high as 51.1%.

  A tubular reaction tube having an effective inner diameter of 16 mm was filled with 2 ml of the catalyst A, and a mixed gas having a carbon monoxide / hydrogen ratio of 1/2 was supplied. The reaction was carried out at a mixed gas supply amount per catalyst (GHSV) of 2000 / Hr, 0.6 MPaG. The reaction temperature was set to 250 ° C., the temperature was increased gradually to 400 ° C. in increments of 25 ° C., and the reactivity was monitored while analyzing the composition of the product gas.

= Summary of reaction conditions =
Catalyst: Catalyst A
Catalyst amount: 2 ml
Source gas: Carbon monoxide / hydrogen ratio = 1/2 mixed gas supply amount (GHSV): 2000 (/ Hr)
Supply pressure: 0.6 (MPaG)
Reaction temperature: 250 ° C. to 400 ° C. (Evaluated at a temperature at which the carbon monoxide conversion rate is 99% or more. If it is not 99% or more, evaluate at a carbon monoxide conversion rate at 400 ° C.)

(result of analysis)
For the analysis of the product gas, a gas chromatograph was used, and the conversion rate of carbon monoxide gas and the amount of C1 to C13 hydrocarbons in the product gas were determined from the analysis results.
The produced gas includes a mixed gas as a raw material and a saturated hydrocarbon gas produced by the reaction, and methane (C1) is 61%, ethane (C2) is 15.9%, and propane is (C3) 17.7%. , Butane was (C4) 0.1%. In addition, it was found that pentane, hexane, heptane and 5.3% of C1-C7 unsaturated hydrocarbon (C5 +) were contained. C8 or higher hydrocarbons were below the detection limit or in trace amounts. Moreover, the converted calorific value was 47.6 MJ / Nm ³ .

  In addition, the amount of generated gas (selectivity), the conversion rate, and the converted calorific value in the present invention are obtained by Equation 1.

[Example 2]
In Example 2, a catalyst for producing a high calorie gas in which the metal oxide support was changed was produced, and a reaction test 2 relating to the production of the high calorie gas was conducted.
In Example 2, the reactants (a2) to (e) are used.
(A2) 10 g of spherical alumina having a diameter of 2 to 4 mm
(B) Aqueous solution containing 1.45 g of iron (III) nitrate nonahydrate (Fe (NO ₃ ) ₃ .9H ₂ O) (c) 0.375N aqueous sodium hydroxide solution (d) 0.3% hydrazine Aqueous solution (e) An aqueous solution containing 0.43 g of ruthenium (III) chloride (ruthenium content: 47.3 mass%)

(Iron supported alumina)
Iron-supported alumina was obtained by the impregnation method and the firing method in the same manner as in Example 1 except that the support (a2) was used instead of the support (a).

(Iron-ruthenium-supported alumina: catalyst B)
Except for using the iron-supporting alumina, an iron-ruthenium-supporting alumina was obtained as a catalyst for producing a high calorie gas by a wet reduction method in the same manner as in Example 1. This high calorie gas production catalyst is referred to as catalyst B.

Example 3
In Example 3, a catalyst for producing a high calorie gas in which the amount of ruthenium carried was variously changed was produced, and a reaction test 3 relating to the production of the high calorie gas was conducted.
In Example 3, the reactants (a) to (e6) are used.
(A) 10 g of spherical titania having a diameter of 2 to 4 mm
(B2) Aqueous solution containing 0.96 g of iron (III) chloride hexahydrate (FeCl ₃ .6H ₂ O) (c) 0.375N aqueous sodium hydroxide solution (d) 0.3% aqueous hydrazine solution (e2) Aqueous solution (e3) containing 0.11 g of ruthenium (III) chloride (ruthenium content 47.3% by mass) Aqueous solution (e) containing 0.22 g of ruthenium (III) chloride (ruthenium content 47.3% by mass) An aqueous solution (e4) containing 0.43 g of ruthenium (III) chloride (ruthenium content 47.3 mass%) An aqueous solution (e5) containing 0.86 g of ruthenium (III) chloride (ruthenium content 47.3 mass%) An aqueous solution (e6) containing 1.3 g of ruthenium (III) chloride (ruthenium content 47.3 mass%) 1.7 g of ruthenium (III) chloride (ruthenium content 4) Aqueous solution containing .3% by weight)

(Iron-supporting titania)
The carrier (a) is impregnated with the entire amount of the iron chloride aqueous solution (b2) and dried. Furthermore, the obtained support | carrier was immersed in sodium hydroxide aqueous solution (c), and iron was fix | immobilized on the support | carrier. This carrier was washed with water and dried, then wet-reduced with 90 ml of hydrazine aqueous solution (d) for 1 hour at room temperature, washed with water and dried to obtain iron-supported titania by impregnation and wet reduction.

(Iron-ruthenium-supported titania: catalysts C to H)
For the production of high calorie gas by the impregnation method and the wet reduction method in the same manner as in Example 1 except that the iron-supported titania is used and the ruthenium chloride aqueous solutions (e) to (e6) are used instead of the ruthenium chloride aqueous solution (e). As a catalyst, iron-ruthenium-supported titania was obtained. This high calorie gas production catalyst is referred to as catalysts C to H in order.

Example 4
In Example 4, a catalyst for producing a high calorie gas in which the amount of iron carried was variously changed was produced, and a reaction test 4 relating to the production of the high calorie gas was conducted.
In Example 4, the following reagents (a) to (e) are used.
(A) 10 g of spherical titania having a diameter of 2 to 4 mm
(B3) Aqueous solution containing 0.24 g of iron (III) chloride hexahydrate (FeCl ₃ .6H ₂ O) (b4) 0.48 g of iron (III) chloride hexahydrate (FeCl ₃ .6H) Aqueous solution containing ₂ O) (b5) Aqueous solution containing 1.44 g of iron (III) chloride hexahydrate (FeCl ₃ .6H ₂ O) (b6) 4.8 g of iron (III) chloride hexahydrate (C) 0.375N sodium hydroxide aqueous solution (d) 0.3% hydrazine aqueous solution (e) 0.43 g of ruthenium (III) chloride (ruthenium content 47.3) containing the product (FeCl ₃ .6H ₂ O) Aqueous solution)

(Iron-supporting titania)
(Iron-ruthenium-supported titania: catalysts IL)
Iron-ruthenium-supported titania as a catalyst for production of high calorie gas by impregnation method and wet reduction method in the same manner as in Example 3 except that iron chloride (b3) to (b6) was used instead of iron chloride aqueous solution (b2). Got. This catalyst for high calorie gas production is referred to as Catalysts I to L in order.

Example 5
In Example 5, a catalyst for producing a high calorie gas in which the supported iron group element was changed was produced, and a reaction test 5 relating to the production of the high calorie gas was conducted.
In Example 5, the reactants (a) to (e) are used.
(A) 10 g of spherical titania having a diameter of 2 to 4 mm
(B7) Aqueous solution containing 0.99 g of cobalt (III) chloride hexahydrate (CoCl ₃ .6H ₂ O) (c) 0.375N aqueous sodium hydroxide solution (d) 0.3% aqueous hydrazine solution (e) An aqueous solution containing 0.43 g of ruthenium (III) chloride (ruthenium content: 47.3 mass%)

(Cobalt-supported titania)
(Cobalt-ruthenium-supported titania: catalyst M)
Cobalt-ruthenium-supporting titania was obtained as a catalyst for producing a high calorie gas in the same manner as in Example 3 except that cobalt chloride (b7) was used instead of the iron chloride aqueous solution (b2). This high calorie gas production catalyst is referred to as catalyst M.

[Comparative Example 1]
In Comparative Example 1, a catalyst for producing a high calorie gas not carrying an iron group element was produced, and a reaction test 6 relating to the production of the high calorie gas was conducted.
In Comparative Example 1, the reactants (a) to (e) are used.
(A) 10 g of spherical titania having a diameter of 2 to 4 mm
(A2) 10 g of spherical alumina having a diameter of 2 to 4 mm
(C) 0.375N sodium hydroxide aqueous solution (d) 0.3% hydrazine aqueous solution (e) An aqueous solution containing 0.43 g of ruthenium (III) chloride (ruthenium content: 47.3 mass%)

(Ruthenium-supported titania: catalyst N)
Ruthenium-supporting titania was obtained as a catalyst for producing a high calorie gas in the same manner as in Example 4 except that the aqueous iron chloride solution (b2) was not used. This high calorie gas production catalyst is referred to as catalyst N.

(Ruthenium-supported alumina: catalyst O)
Ruthenium-supported alumina was obtained as a catalyst for producing a high calorie gas in the same manner as in Example 4 except that the aqueous iron chloride solution (b2) was not used and the alumina carrier (a2) was used instead of the titania carrier (a). This high calorie gas production catalyst is referred to as catalyst O.

[Comparative Example 2]
In Comparative Example 2, a high calorie gas production catalyst in which ruthenium was supported on a carrier by a calcination method was used instead of the wet reduction method, and a reaction test 7 relating to the high calorie gas production was conducted.
In Comparative Example 2, the reactants (a) to (e7) are used.
(A) 10 g of spherical titania having a diameter of 2 to 4 mm
(B) Aqueous solution containing 1.45 g of iron (III) nitrate nonahydrate (Fe (NO ₃ ) ₃ .9H ₂ O) (c) 0.375N aqueous sodium hydroxide solution (d) 0.3% hydrazine Aqueous solution (e7) 5.15 g of ruthenium (III) nitrate (Ru (NO ₃ ) ₃ ) aqueous solution (ruthenium equivalent concentration 3.9% by mass)

(Iron-supporting titania)
In the same manner as in Example 1, iron-supported titania was obtained.

(Iron-ruthenium-supported titania: catalyst P)
The iron-supporting titania is impregnated with the entire amount of the aqueous ruthenium nitrate solution (e7) and dried. Furthermore, the obtained carrier was calcined at 400 ° C. for 6 hours to obtain iron-ruthenium-supporting titania as a catalyst for producing a high calorie gas. This high calorie gas production catalyst is referred to as catalyst P.

[Comparative Example 3]
In Comparative Example 3, after supporting ruthenium by a wet reduction method, a catalyst for producing a high calorie gas carrying an iron group element was produced, and a reaction test 8 relating to the production of the high calorie gas was conducted.
In Comparative Example 3, the reactants (a) to (e7) are used.
(A) 10 g of spherical titania having a diameter of 2 to 4 mm
(B) Aqueous solution containing 1.45 g of iron (III) nitrate nonahydrate (Fe (NO ₃ ) ₃ .9H ₂ O) (c) 0.375N aqueous sodium hydroxide solution (d) 0.3% hydrazine Aqueous solution (e7) An aqueous solution containing 0.43 g of ruthenium (III) chloride (ruthenium content: 47.3 mass%)

(Ruthenium-bearing titania)
As in Comparative Example 1, ruthenium-supporting titania was obtained.

(Ruthenium-iron supported titania: Catalyst Q)
The ruthenium-supporting titania is impregnated with the entire amount of the iron nitrate aqueous solution (b) and dried. Furthermore, the obtained carrier was calcined at 400 ° C. for 6 hours to obtain ruthenium-iron-supporting titania as a catalyst for producing a high calorie gas. This high calorie gas production catalyst is referred to as catalyst Q.

[Reaction tests 2-8]
A mixed gas containing hydrogen and carbon monoxide was reacted under the same test conditions as in the reaction test 1 except that the catalysts B to Q were used instead of the catalyst A.

Example 6
In Example 6, a catalyst for producing a high calorie gas in which ruthenium was supported by a wet reduction method as in Example 1 was produced, and a reaction test 9 relating to the production of the high calorie gas was conducted.
In Example 6, the reactants (a) to (e) are used.
(A) 10 g of spherical titania having a diameter of 2 to 4 mm
(B) Aqueous solution containing 1.45 g of iron (III) nitrate nonahydrate (Fe (NO ₃ ) ₃ .9H ₂ O) (c) 0.375N sodium hydroxide aqueous solution (d) 0.3% hydrazine Aqueous solution (e) containing 0.43 g of ruthenium (III) chloride (ruthenium content 47.3 mass%)

(Iron-supporting titania)
In the same manner as in Example 1, iron-supported titania was obtained.
(Iron-ruthenium-supported titania: catalyst R)
In the impregnation of ruthenium, for the production of high calorie gas by the impregnation method and the wet reduction method in the same manner as in Example 1 except that the iron-supported titania was impregnated with the specified amount of ruthenium chloride aqueous solution (e) in one time. As a catalyst, iron-ruthenium-supported titania was obtained. This high calorie production catalyst is referred to as catalyst R.

[Reaction Test 9]
A reaction test was conducted in the same manner as in Example 1. The degree of dispersion of ruthenium as measured by the carbon monoxide adsorption method was 23.7%. The ruthenium dispersion degree in Example 1 was lower than 51.1% because in Example 1, the ruthenium chloride solution impregnated in two portions was impregnated once, so that the ruthenium was well dispersed. It is thought that it was not possible.

[Comparative Example 4]
In Comparative Example 4, a catalyst for producing a high calorie gas in which ruthenium was supported by a firing method was produced, and a reaction test 10 relating to the production of the high calorie gas was conducted.
In Comparative Example 4, the reactants (a) to (e7) are used.
(A) Spherical titania having a diameter of 2 to 4 mm (b) Aqueous solution containing 1.45 g of iron (III) nitrate nonahydrate (Fe (NO ₃ ) ₃ .9H ₂ O) (c) 0.375N hydroxide Sodium aqueous solution (d) 0.3% hydrazine aqueous solution (e7) 5.15 g of ruthenium (III) nitrate (Ru (NO ₃ ) ₃ ) aqueous solution (ruthenium equivalent concentration 3.9% by mass)

(Iron-supporting titania)
In the same manner as in Example 1, iron-supported titania was obtained.
(Iron-ruthenium-supported titania: catalyst T)
An iron-ruthenium-supported titania was obtained as a catalyst for producing a high calorie gas by the impregnation method and the firing method in the same manner as in Comparative Example 2 except that the firing time at 400 ° C. was 1 hour. This high calorie production catalyst is referred to as catalyst T.

[Reaction Test 10]
A reaction test was conducted in the same manner as in Example 1.

Example 7
In Example 7, a catalyst for producing a high calorie gas in which ruthenium and iron were simultaneously supported on a carrier by a wet reduction method was produced, and a reaction test 11 relating to the production of the high calorie gas was conducted.
In Example 7, the reactants (a) to (d) are used.
(A) 10 g of spherical titania having a diameter of 2 to 4 mm
(B8) An aqueous solution containing 0.43 g of ruthenium (III) chloride (ruthenium content 47.3 mass%) and 0.96 g of iron (III) chloride hexahydrate (FeCl ₃ .6H ₂ O) (c ) 0.375N sodium hydroxide aqueous solution (d) 0.3% hydrazine aqueous solution

(Ruthenium-iron supported titania: catalyst U)
Ruthenium-iron supported as a catalyst for high calorie gas production by the impregnation method and wet reduction method in the same manner as in Example 3 except that the aqueous solution of ruthenium chloride / iron chloride (b8) was used instead of the aqueous solution of iron chloride (b2). Obtained titania. This high-calorie production catalyst is referred to as catalyst U.

[Reaction Test 11]
A reaction test was conducted in the same manner as in Example 1.

Example 8
In Example 8, after supporting ruthenium by a wet reduction method, iron is supported by a wet reduction method, a catalyst for producing a high calorie gas in which the amount of iron to be carried is variously changed is manufactured, and the reaction relating to the production of the high calorie gas Test 12 was conducted.
In Example 7, the following reactants (a) to (e11) are used.
(A) 10 g of spherical titania having a diameter of 2 to 4 mm
(B9) An aqueous solution containing 0.43 g of ruthenium (III) chloride (ruthenium content: 47.3 mass%) (c) 0.375N aqueous sodium hydroxide solution (d) 0.34% aqueous hydrazine solution (e8) 0.24 g An aqueous solution containing iron (III) hexahydrate (FeCl ₃ .6H ₂ O) (e9) 0.96 g of an aqueous solution containing iron (III) chloride hexahydrate (FeCl ₃ .6H ₂ O) (E10) An aqueous solution containing 1.92 g of iron (III) chloride hexahydrate (FeCl ₃ .6H ₂ O) (e11) 2.88 g of iron (III) chloride hexahydrate (FeCl ₃ .6H) ₂ O) containing aqueous solution

(Ruthenium-bearing titania)
Ruthenium-supporting titania was obtained by the impregnation method and wet reduction method in the same manner as in Example 3 except that the ruthenium chloride aqueous solution (b9) was used instead of the iron chloride aqueous solution (b2).

(Ruthenium-iron supported titania: catalysts V to Y)
Ruthenium-iron supported as a catalyst for high calorie gas production by the impregnation method and wet reduction method in the same manner as in Example 3 except that the aqueous iron chloride solutions (e8) to (e11) were used instead of the aqueous ruthenium chloride solution (e). Obtained titania. These high calorie production catalysts are referred to as catalysts V, W, X, and Y in this order.

[Reaction Test 12]
A reaction test was conducted in the same manner as in Example 1.

(result of analysis)
The analysis results of the reaction tests 1 to 12 are summarized in Table 1.

  From Table 1, for catalysts A to O, R, and U to Y, all of ruthenium can efficiently produce a high calorie gas when dispersed with a high dispersity of 20% or more with respect to the support. I understand that. (Examples 1-8, Comparative Example 1) Further, in particular, when catalysts E, U, and W are compared, when ruthenium and iron are supported by a wet reduction method, the catalyst loading order greatly affects the activity of the catalyst. It can be read that there is no effect.

On the other hand, when comparing the catalyst A and the catalyst Q, the catalyst Q is supported in the order of ruthenium-iron, but the ruthenium dispersity with respect to the metal oxide carrier is low, and as a method for producing a catalyst for producing high calorie gas In order to produce a catalyst for producing high-calorie gas with high activity, it is preferable that the catalyst component is loaded in the production method (Example 1, catalyst A) in which ruthenium is loaded after iron is loaded on the carrier. It can be seen that it is.
Further, when comparing catalyst Q and catalyst W, if the loading order of the catalyst components is iron-ruthenium, iron can achieve a relatively high degree of ruthenium dispersion even if it is fired, but if the order is reversed, ruthenium It is found that it is preferable to carry the iron by a wet reduction method, and more preferably, iron is also carried by the wet reduction method.

  Further, comparing the catalyst P and the catalyst T, in the case of ruthenium firing support, at 400 ° C., there is no significant difference in the activity of the catalyst between the firing for 6 hours and the firing for 1 hour. It turns out that it is enough.

  Here, it can be seen that when ruthenium is supported from the catalyst R by the wet reduction method, a high degree of dispersion of ruthenium can be realized regardless of the iron supporting method.

  Further, when the catalyst Q and the catalyst A are compared, it can be seen that the dispersity of ruthenium in the catalyst Q is low. The reason why the dispersity in the catalyst Q is low is considered to be that wet-supported ruthenium has been subjected to a calcination action when it is supported by calcination of iron, and the calcination condition of iron is made difficult to cause ruthenium calcination. Therefore, it is considered that a high degree of dispersion of ruthenium can be maintained. This is because the activity of the catalyst in which ruthenium was supported on the alumina support by the wet reduction method and then calcined and supported on cobalt at 200 ° C. at a reaction temperature of 350 ° C. was good (CO conversion 99.5%), and It is clear from the fact that the CO conversion is less than 90% (catalysts P, Q, T) unless the ruthenium dispersion is 20% or more. Therefore, even when the loading order of ruthenium and iron is not taken into consideration, it is a preferable condition for producing a catalyst for producing a high calorie gas by loading ruthenium by a wet reduction method (Comparative Example 3, catalyst Q). it is conceivable that.

  On the other hand, when ruthenium is supported on the metal oxide support, the case where the entire amount is supported at once (catalyst R) and the case where the entire amount is supported twice (catalyst A) are divided twice. It was found that the case can achieve a higher degree of dispersion. That is, the smaller the amount of catalyst to be supported per operation, the less likely it is to agglomerate, so the degree of dispersion tends to increase, and the agglomeration of the catalyst supported in subsequent operations is also kept low. I understand.

  Next, according to Example 2, it became clear that titania and alumina can be effectively used as the metal oxide support. In addition, when titania is used, high calorie gas can be produced at the lowest reaction temperature, and thus it has been found that titania is preferable as the carrier.

  Next, according to Example 3, as shown in the catalysts C to H in Table 1 and FIG. 1, when the amount of ruthenium supported on the carrier of the catalyst for producing high calorie gas decreases, the activity as a catalyst decreases, If the reaction temperature is not increased, it tends to be difficult to produce high-calorie gas, and the energy-saving property of producing high-calorie gas tends to decrease. On the other hand, as the amount of ruthenium supported increases, the dispersibility of ruthenium decreases, the methane selectivity of the gas component contained in the product gas increases, and the converted calorific value of the product gas tends to decrease. Since it cannot withstand the use as a high calorie gas, it tends to cause problems such as adjustment of components after reaction. Therefore, it is preferable that the load of ruthenium is 1% by mass to 8% by mass. It can also be seen that the amount of ruthenium supported is more preferably 2% by mass to 6% by mass.

  Next, according to Example 4 (see part of Example 3), as shown in Catalysts 1 and L in Table 1 and FIG. When the amount of carbon dioxide increases, the activity as a catalyst decreases, and it tends to be difficult to produce a high calorie gas unless the reaction temperature is raised, and the energy saving property of the production of high calorie gas tends to be lowered. On the other hand, when the amount of iron supported on the carrier of the catalyst for producing high calorie gas is reduced, the dispersibility of ruthenium is improved and the methane selectivity of the gas component contained in the product gas is increased, and the conversion heat of the product gas is converted. The amount tends to be low. Therefore, it can be seen that the preferable loading amount of iron is 0.5 mass% to 10 mass%, more preferably 0.5 mass% to 3 mass%.

  Further, from Example 5, it can be seen that, as the iron group element, cobalt can be used in addition to iron from the catalysts E and M in Table 1. However, when cobalt is used, the methane selectivity of the gas component contained in the generated gas is higher than in the case of iron, and the converted calorific value of the generated gas tends to be low. Since it cannot withstand the intended use, it tends to cause problems such as adjustment of components after reaction. Therefore, it can be seen that iron is preferably used as the iron group element.

  Further, according to Comparative Example 1, when no iron group element is supported from the catalysts N and O in Table 1, the methane selectivity of the gas component contained in the generated gas is high, and almost no high calorie gas can be obtained. Was confirmed. Moreover, the effect by the carrier of high calorie gas productivity in the catalyst for high calorie gas production can be compared, and it can be read that even the catalyst N of only titania has the ability to produce high calorie gas.

In the present invention, whether or not the product gas produced by each catalyst is called a high calorie gas is determined by whether or not the generated gas produced by the catalyst N exceeds the calorific value. If a saturated hydrocarbon gas having 2 to 4 carbon atoms is significantly generated and contained as one of the main components, it may be considered as a catalyst capable of producing a high calorie gas. Preferably, it is desired to produce a calorific product gas having a converted calorific value of 45 MJ / Nm ³ or more that can be supplied as city gas without adjusting calories by adding other gases (rather by dilution with methane).

[Others]
Examples of ruthenium compounds and nitrates and hydrochlorides used as iron compounds are mixed in the impregnation method. However, in the impregnation method, the final form of the supported compound is generally stable metal or stable oxidation by reduction or oxidation. It is known that almost the same result can be obtained with any anion relative to the cation of the starting material. Therefore, in the method for producing a high calorie gas production catalyst of the present invention, any ruthenium compound or iron compound as a starting material may be used.

  The carrier has a spherical shape, but any shape such as a pellet shape, a ring shape, a tube shape, or an indefinite shape can be adopted. Moreover, in the said reaction test, although it was used with the form filled with a cylindrical container, it can be used with arbitrary application forms, such as installing as a honeycomb-shaped filter.

  Employing the wet reduction method eliminates the problem of post-treatment of a reducing gas such as hydrogen gas, which is necessary when handling vapor phase reduction and requires care. In this embodiment, a hydrazine solution is used in the wet reduction method, but a reducing agent such as formalin, formic acid, or a sodium borohydride solution can also be used.

Claims (17)

  A catalyst for producing a high calorie gas, in which ruthenium and an iron group element are supported on a metal oxide support, and the degree of dispersion of ruthenium is 20% or more.   2. The catalyst for producing high calorie gas according to claim 1, wherein ruthenium is supported on the metal oxide support by a wet reduction method.   The catalyst for producing a high calorie gas according to claim 1 or 2, wherein ruthenium is further supported by a wet reduction method on a metal oxide support on which an iron group element is supported.   The catalyst for producing a high calorie gas according to claim 1 or 2, wherein an iron group element is further supported by a wet reduction method on a metal oxide support in which ruthenium is supported on the metal oxide support by a wet reduction method.   The high-calorie gas production catalyst according to any one of claims 1 to 4, wherein the iron group element is iron.   The catalyst for producing a high calorie gas according to any one of claims 1 to 5, wherein the metal oxide support is mainly composed of titania.   The catalyst for high calorie gas production according to any one of claims 1 to 6, wherein iron is supported on the metal oxide support in an amount of 0.5 mass% to 10 mass%.   The catalyst for high calorie gas production according to any one of claims 1 to 7, wherein 1 to 8% by mass of ruthenium is supported on the metal oxide support.   A method for producing a catalyst for producing a high calorie gas in which ruthenium and an iron group element are dispersed and supported on a metal oxide support so that the degree of dispersion of ruthenium is 20% or more.   The method for producing a high calorie gas production catalyst according to claim 9, wherein ruthenium is supported on the metal oxide support by a wet reduction method.   The method for producing a high calorie gas production catalyst according to claim 9 or 10, wherein the iron oxide is supported on the metal oxide support, and then ruthenium is supported by a wet reduction method.   The method for producing a catalyst for producing high calorie gas according to claim 9 or 10, wherein ruthenium is supported on a metal oxide support by a wet reduction method, and then an iron group element is supported by a wet reduction method.   The method for producing a catalyst for producing high calorie gas according to any one of claims 9 to 12, wherein the iron group element is iron.   The method for producing a high calorie gas production catalyst according to any one of claims 9 to 13, wherein the metal oxide support is mainly composed of titania.   The method for producing a high calorie gas production catalyst according to any one of claims 9 to 14, wherein iron is supported on the metal oxide support in an amount of 0.5 mass% to 10 mass%.   The method for producing a catalyst for producing a high calorie gas according to any one of claims 9 to 15, wherein 1 mass% to 8 mass% of ruthenium is supported on the metal oxide support.   A mixed gas containing hydrogen and carbon monoxide is reacted in the presence of the catalyst for producing a high calorie gas according to any one of claims 1 to 8, and a high calorie gas mainly composed of a lower saturated hydrocarbon is produced. High calorie gas manufacturing method to manufacture.

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